Data source is taking long time in CRM

You can see this data source is taking around 1 hour in particular area .it is taking almost 1hr to load only 18k records .

I have identified where it is taking time in source code but not getting proper solution to improve the performance (I have raised one OSS as well ), SAP suggested few notes to improve performance (before, this data source was taking around 50mins to load only 10k records, it is giving better performance compared to previous load) after applying those notes we still getting performance issue .

P:S This is issue is happening due to huge change document number of BP , we have a piece of standard code in this data source where it is taking time when change document is requested for BP.